android_prebuilts do not sync on Tiramisu

[mii000]

The android_prebuilts_clang_host_linux-x86_clang-r475365b and android_prebuilts_clang_host_linux-x86_clang-r487747 do not sync because these projects don't have a Tiramisu branch on the elixir-gitlab remote.

Proof:

<remote name="elixir-gitlab"
fetch="https://gitlab.com/projectelixiros/"
revision="refs/heads/Tiramisu" />

Repo sync error messages:

Fetching:  0% (0/2) 0:05 | 1 job | 0:04 android_prebuilts_clang_host_linux-x86_clang-r475365b @ prebuilts/clang/host/linux-x86/clang-r475365b
fatal: couldn't find remote ref refs/heads/Tiramisu

android_prebuilts_clang_host_linux-x86_clang-r475365b:
fatal: couldn't find remote ref refs/heads/Tiramisu
android_prebuilts_clang_host_linux-x86_clang-r475365b: sleeping 4.0 seconds before retrying
fatal: couldn't find remote ref refs/heads/Tiramisu
error: Cannot fetch android_prebuilts_clang_host_linux-x86_clang-r475365b from https://gitlab.com/projectelixiros/android_prebuilts_clang_host_linux-x86_clang-r475365b
Fetching:  0% (0/2) 0:10 | 1 job | 0:04 android_prebuilts_clang_host_linux-x86_clang-r487747 @ prebuilts/clang/host/linux-x86/clang-r487747
fatal: couldn't find remote ref refs/heads/Tiramisu

android_prebuilts_clang_host_linux-x86_clang-r487747:
fatal: couldn't find remote ref refs/heads/Tiramisu
android_prebuilts_clang_host_linux-x86_clang-r487747: sleeping 4.0 seconds before retrying
fatal: couldn't find remote ref refs/heads/Tiramisu
error: Cannot fetch android_prebuilts_clang_host_linux-x86_clang-r487747 from https://gitlab.com/projectelixiros/android_prebuilts_clang_host_linux-x86_clang-r487747
Fetching: 100% (2/2), done in 11.348s
Checking out:  99% (1185/1188), done in 2m5.353s
error: Cannot checkout android_prebuilts_clang_host_linux-x86_clang-r475365b: ManifestInvalidRevisionError: revision refs/heads/Tiramisu in android_prebuilts_clang_host_linux-x86_clang-r475365b not found
error: in `sync -c -j 8 --force-sync --no-clone-bundle --no-tags`: revision refs/heads/Tiramisu in android_prebuilts_clang_host_linux-x86_clang-r475365b not found

It seems enough to just set these to revision=master on the snippets/elixir.xml file

  <project path="prebuilts/clang/host/linux-x86/clang-r475365b" name="android_prebuilts_clang_host_linux-x86_clang-r475365b" remote="elixir-gitlab" clone-depth="1" />
  <project path="prebuilts/clang/host/linux-x86/clang-r487747" name="android_prebuilts_clang_host_linux-x86_clang-r487747" remote="elixir-gitlab" clone-depth="1" />

I made a fork with these changes and the sync succeeds. Pull request is here.